1. Field of the Invention
The present invention relates to a multi-channel spectrophotometric measuring device for simultaneous analysis of a large number of specimens with different items to be tested, to be applied for example, in a field such as biochemical automatic analysis or the like.
2. Description of the Prior Art
Recently, owing to the rapid increase in the number of specimens to be dealt with, arising from greater importance attached to clinical examinations, there has been an increasing demand for labor saving and simultaneous analysis of many items, with various methods being developed for the purpose, as for example, a multi-channel two wavelength spectrophotometer disclosed in Japanese Laid Open Patent Application Tokkosho 53-122474, which has come to be employed in a wide range of applications. The spectrophotometer referred to above is so arranged that transmitting light from a large number of sample cells (flow cells in this case) arranged in the direction of an X axis is focused in a slit elongated in the same X axis direction, and is then subjected to spectral analysis by a diffraction grating or the like so as to be projected onto a wavelength dispersion optical system disposed in such a manner that the spectral range of light transmitted through each cell and subjected to the spectral diffraction becomes spectrum dispersed in the direction of a Y axis. Also there is provided a light receiving portion of the spectrum for the above monochromatic light, and this light receiving portion has a detecting portion including more than two detecting elements disposed in the Y direction, with the respective detecting portions being arranged in a platelike configuration in the X axis direction so as to correspond to the positions where the respective spectral bands appear.
By the conventional arrangement as described above, selection and combination of reference wavelength and sample wavelength to be determined by the examination items of the specimens are facilitated making it possible to allow simultaneous analysis of many specimens, but owing to the necessity of maintaining an optical path length required for the analysis, since the flow cells are disposed to intersect at right angles with respect to the irradiation optical axis, the diameter of the flow cell cannot be excessively reduced, and due to the fact that the position of the flow cell is restricted to the predetermined position of the above optical system, the length of the sample suction flow path, for example, in order to successively introduce a reagent separately poured into the specimens from containers of the reaction samples into the flow cell, cannot be reduced beyond a predetermined length, and consequently, extra samples are required for eliminating such carry-over, thus resulting in the disadvantage that sufficient analysis cannot be effected on samples of small quantity.